CSS questions

Hi,

I am new to PHP and CodeIgniter, I have quite a lot to learn  .

I started using CSS, but I fell I can make better use. Here is what I am talking about:

Code:

           .row_col1{
              background-color: red;
              text-align: center;
              width: 200px;
              font-family: verdana;              
              color: black;
              font-size: xx-large;
              font-weight: bold;
           }

           .row_col2{
              background-color: yellow;
              text-align: center;
              width: 200px;
              font-family: verdana;
              color: black;
              font-size: xx-large;
              font-weight: bold;                
           }

           .row_col3{
               background-color: yellowgreen;
               text-align: center;
               width: 200px;
               font-family: verdana;
               color: black;
               font-size: xx-large;
               font-weight: bold;
           }  

As you can see, the only difference between the three is the color.

I would like to create only one style and add the color when I add rows, but that doesn't work unfortunately. I tried something like this:

Code:

$row1 = [
  'data' => 'Some text',
  'class' => 'row_without_color',
  'background-color' => 'yellow'
]

The generated code was like this:

... <class = 'row_without_color' background-color = yellow ...

Thing is the background-color was not applied.

What am I doing wrong ?

Thanks